I powder coat everything I cast. The powder coat doesn't totally eliminate the need for a gas check for really fast loads, but you can push bullets much faster with no leading than you could with just traditional lube. Plus there is considerably less smoke and lube fouling. I consider powder coating to be superior for 90% of cast bullet applications.

Also, I don't know if I mentioned previously, but the coating has its own hardness separate from the lead underneath. You can read some forums about this, but in my 1000s of cast bullets I've never done more than eyeball estimate my alloy, then once I powder coat the bullets I quench them in water. I've never dealt with lead fouling, at least not so much that a couple run-throughs of the bore snake can't take care of.